crossbeam scopre test

crossbeam_scope_test.rs

// https://docs.rs/crossbeam/0.7.3/crossbeam/thread/index.html#structs

// need to add the following dependency to Cargo.toml
// 
// [dependencies]
// crossbeam = "0.7"

use crossbeam::thread;

fn main() {
    let mut var = vec![1, 2, 3];
    
    thread::scope(|s| {
        s.spawn(|_| {
            var.push(4);
            println!("A child thread borrowing `var`: {:?}", var);
        });
    }).unwrap();

    println!("Now got back ownership of `var`: {:?}", var);
}

// use std::thread;
// 
// fn main() {
//     let mut var = vec![1, 2, 3];
//    
//     thread::spawn(move || {
//         var.push(4);
//         println!("A child thread borrowing `var`: {:?}", var);
//     });
// 
//     println!("Now got back ownership of `var`: {:?}", var); // compile error, ownership of `var` moved to the above thread.
// }